Diagnostic Monitor to Guide Early Goal-Directed Therapy in Emergency Departments Summary Mortality rates for critically ill patients are unnecessarily high because of the extended time (6-7 hrs) that it usually takes for diagnoses to be rendered in Emergency Departments while waiting to be sent to an appropriate intensive care unit (ICU) for treatment. What is needed is an instrument that can immediately diagnose such patients and provide therapy guidelines that would allow Emergency Department personnel to initiate life-saving medical treatment during the first 6 hours after arrival to Emergency. While there are several noninvasive monitors that measure cardiac output (CO) and various other hemodynamic parameters, they are limited by their inability to monitor sufficient parameters in order to quantify and correct for physiological interferences. The proposed development has the capability to acquire these critical parameters simultaneously. Since all "interfering" elements are physiological parameters that have significance for disease diagnosis and patient management, the proposed monitor is referred to as an Emergency Diagnostic Monitor (EDM). The proposed EDM provides a sufficient number of measurements (referred to as a "complete set") to assure accuracy of any one of them. This monitor is noninvasive, and patient risk is virtually eliminated by using the lung as a port for both injection of gases (in tracer concentrations) and their measurements. Initial tests of the methodology proved successful in experimental animals. However, studies with chronic obstructive pulmonary disease (COPD) subjects revealed that asynchronous ventilation was the cause of significant error. Therefore, in order for the monitor to address a wide range of pathologies, additional cardiopulmonary measurements are needed which allow quantification of asynchronous ventilation and its effects on other parameters. Therefore, a major task is to solve the problem of asynchronous ventilation by use of a dual injection scheme, which requires measurement of additional inert (tracer) gases. In order for the concept of a "complete set" to be economically viable, the gas analyzer must be capable of monitoring thirteen gases economically and with accuracy found in only highly quantitative instruments. It must also meet cost constraints of medical devices. A significant advance in medical mass spectroscopy has been the development of a patented piezo controlled inlet valve (developed by this group). From this, a low power commercial medical mass spectrometer (Solo(R)) was developed which displayed a high degree of reliability in the hospital environment. Modification of Solo(R) will allow monitoring of the additional gases needed to correct for ventilation phasing and is one of the tasks of this proposal. The EDMs diagnostic capability is enhanced by a measurement set that includes a total of 18 physiological parameters. Its validation in septic shock patients for early goal-directed therapy (EGDT) guidance is the main focus of this Phase I. PUBLIC HEALTH RELEVANCE: Diagnostic Monitor to Guide Early Goal-Directed Therapy in Emergency Departments Narrative Mortality rates for critically ill patients are unnecessarily high because of the extended time (6-7 hrs) that it usually takes for diagnoses to be rendered in Emergency Departments while waiting to be sent to an appropriate intensive care unit (ICU) for treatment. What is needed is a noninvasive instrument that can immediately diagnose such patients and provide therapy guides to allow Emergency Department personnel to initiate life-saving medical treatment before ICU treatment is available. The goal of this project is to develop and test a noninvasive instrument with the reliability and comprehensiveness needed to provide earlier detection, of septic shock and practical guidance by Emergency personnel.